Number of Subscriptions per CDC Instance
For best resource utilization, and easiest management, you want to keep the number of CDC Instances and Subscriptions to the minimum.
Rule of Thumb:
- InfoSphere CDC LUW can generally accommodate up to 50 subscriptions per instance (either source or target)
InfoSphere CDC z can generally accommodate up to 20 combined source and target subscriptions per instance and a hard maximum of 50 subscriptions per instance
- Note: For CDC z if you have three or more source subscriptions in an instance, for optimal resource utilization, you need to ensure that the log cache is configured
InfoSphere CDC i can generally accommodate up to 25 source subscriptions per instance, and 25 subscriptions in a target instance
- Note that InfoSphere CDC i does not have the single scrape feature, so each additional subscription will require proportionally extra CPU resource if reading from a single journal. Thus, if you have multiple subscriptions you will achieve better efficiency if separate journals can be used for each subscription